ABSTRACT
The development of current healthcare practices is given by the emergence of new surgical procedures, materials, and medical products. Polymeric materials are present in many of these innovations and certain clinical and cost requirements must be met. The high performance of biomaterials is obtained by controlling surface properties (Aori et al. 2013). The radio frequency (RF) plasmas are generally used for the surface modication of polymers because they produce the sterilization of the products, involve low consumption of chemicals, and it is a solvent-free and dry
8.1 Impact of the Study ....................................................................................... 125 8.2 Plasma Interaction with Substance ............................................................... 127
8.2.1 General Processes at the Interface between the Plasma and the Material ................................................................................ 127
8.2.2 Interaction with a Polymeric Surface ............................................... 128 8.3 Experimental Procedure ............................................................................... 131
8.3.1 Two-Step Treatment .......................................................................... 131 8.3.2 Types of Measurements .................................................................... 131
8.4 Results and Discussions ................................................................................ 132 8.4.1 FTIR Measurements ......................................................................... 132 8.4.2 SEM Measurements .......................................................................... 133 8.4.3 XRD Measurements ......................................................................... 133 8.4.4 Antimicrobial Activity ...................................................................... 133
8.5 Remarks and Future Directions .................................................................... 136 Acknowledgments .................................................................................................. 137 References .............................................................................................................. 137
process. By using precisely controllable processes from RF plasma, the surface can be treated homogeneously and the surface chemistry can be tailored for the required end use (Drobota et al. 2010, Aori 2014). In order to achieve antimicrobial surfaces properties, the research efforts have been turned toward engineering polymer lms loaded with silver and silver nanoparticles (Johnson et al. 1990, Sagripanti 1992). Multilayer lms containing silver nanoparticles were generated by layer-by-layer assembly, comprising catechol used to ligate and reduce silver ions to metallic silver when immersed in an aqueous silver salt solution (Hwang et al. 2011). Different commercial products containing silver have materialized: wound dressings, bandages for burns and chronic wounds, silver and silver nanoparticles-coated catheters, and other medical devices. A number of factors, such as concentration, size, shape, and aggregation, come into play in determining the efciency of silver-based coatings (Liedberg and Lundeberg 1989, Ahearn et al. 2000). One of the most common types of healthcare-associated infection from hospitals is bacteriuria and is owing to the presence of a urinary catheter in the human body, the daily incidence of those urinary tract infections being 3%–10%. The mucosal irritation and catheter-related urinary tract infection (CUTI) are due to the insertion of the urethral catheters which inoculate organisms into the bladder and promote colonization by providing a surface for bacterial adhesion (Vergidis and Patel 2012, Padawer et al. 2015). A CUTI is dened as the new appearance of bacteriuria or funguria with a count of greater than 103 colony-forming units per milliliter (Patel and Arya 2000). Bacteriuria is developed in 10%–30% of patients who are undergoing short-term catheterization (i.e., 2-4 days) while in the case of long-term catheterization, the percents are 90%–100% (Gould et al. 2010, Hooton et al. 2010). About 80% of nosocomial CUTIs are related to urethral catheterization but only 5%–10% are related to genitourinary manipulation. The presence of potentially pathogenic bacteria and an indwelling catheter produce a nosocomial CUTI. The bacteria may gain entry into the bladder during manipulation of the catheter or drainage system, during insertion of the catheter, around the catheter, and after removal (Stark and Maki 1998, Darouiche et al. 1999). The most commonly responsible for CUTI development are enteric pathogens (e.g., Escherichia coli), but Pseudomonas species, Enterococcus species, Staphylococcus aureus, coagulase-negative staphylococci, Enterobacter species, and yeast also are known to cause infection (Riley et al. 1995). Nowadays, there are many studies comparing standard noncoated catheters with silver-coated catheters, and all studies have included patients requiring a catheter in situ for more than 2 days and less than 10 days (Munasinghe et al. 2001, Schumm and Lam 2008). A complete analysis con sisting of eight clinical trials was performed (Saint and Lipsky 1999) in order to establish the effect of silver coatings. When all studies were considered together (four of them using silver-oxide-coated catheters and the other four using silveralloy-coated hydrogel catheters), a statistically signicant benet was seen in all patients with silver-coated catheters. Two randomized prospective studies were performed in order to evaluate the incidence of bacteriuria during short-and intermediate-term catheterization with the silver-alloy-coated hydrogel catheter compared to the standard latex catheter following urological surgery (Verleyen et al. 1999). The authors found that the silver alloy catheter signicantly delayed the onset of bacteriuria in patients catheterized for a median duration of 5 days (range 2-14 days).
